1. Field of the Invention
This invention lies in the field of magnetic tape decks for writing and reading of digital data on and from magnetic tapes. More particularly, it concerns the design of an automatic tape reel latch, which permits quick and easy positioning of the tape reel over the latch, and by pneumatic pressure, provides a strong force applying friction to the reel, in order to drive it at high accelerations.
2. Description of the Prior Art
In the prior art there are a number of different designs of tape reel latches, on which tape reels can be mounted for rotation by a drive shaft of a tape deck. Most of these are of a strictly mechanical design in which a manually operated cam means forces outwardly a plurality of circumferentially spaced friction pads to grip the inner surface of the tape reel and to drive it in synchronism with the rotation of the reel latch and shaft. These mechanical latches have limited range of the cams which can be provided for mechanical control, and because as the friction pads wear, there is no way to adjust, and the friction pressure is reduced. Thus, these prior art latches have not been entirely satisfactory. In the present system, a reel latch which is operated by pneumatic pressure has a greater range of cam action and applies a selected frictional force, which locks the reel to the hub, and to the drive shaft.